Reduced-friction catheter introducer and method of manufacturing and using the same

ABSTRACT

Tear-away and non-tear-away sheath introducers for catheters, methods for making such introducers, and methods for using such introducers are described. The sheath introducers contain movable valves that are encapsulated in a movable housing that allows the valve to move along the axis of the introducer. As the movable valve and housing travel along the axis, a portion of the hub protrudes past the valve and is exposed. As well, the sheath introducers can also contain a stationary valve and housing that can be opened to expose a portion of the hub when a conduit penetrates the stationary valve. In both instances, the protruding portion of the hub contains a friction-free pathway for a catheter into the sheath introducer. The introducers can therefore be used with any catheter, regardless of the size or material, because of the reduced or eliminated frictional force between the catheter and introducer.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/288,959, filed on Nov. 29, 2005, which claims priority toU.S. Provisional Application No. 60/631,397, filed on Nov. 29, 2004, thedisclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to medical devices and methods for manufacturingsuch medical devices. In particular, the invention relates tointroducers for catheters, methods for making such introducers, andmethods for using such introducers. More particularly, the inventionrelates to self-sealing sheath introducers (both tear-away andnon-tear-away), methods for manufacturing such introducers, and methodsof using such introducers in medical procedures.

BACKGROUND OF THE INVENTION

Tear-away sheath introducers (“sheath introducers” or “introducers”) andtheir use as medical devices are well known in the art. See, for exampleU.S. Pat. Nos. 6,814,718, 6,808,520, 6,808,509, 6,796,991, 6,740,101,6,712,791, 6,712,789, 6,695,810, 6,641,564, 6,632,234, 6,623,460,6,599,302, 6,361,559, and 5,558,652, as well as U.S. Patent ApplicationsSer. Nos. 20040260243, 20040254534, 20040176781, 2004006330, 2004097863,and 2002072789, the disclosures of which are incorporated herein byreference. These introducers are used in medical procedures to insert acatheter into the body and provide vascular access to the vessel of apatient. The catheters are inserted via the introducers by first using aneedle to create an access site. A dilator is then used to dilate theaccess site to allow a larger-diameter sheath introducer to beintroduced into the vessel through the access site. The catheter is theninserted through the sheath introducer and into the vessel. After thecatheter has been inserted, the sheath introducer is removed, leavingthe catheter in the vessel.

As shown in FIG. 19, conventional tear-away (or split) sheathintroducers 100 usually contain four major components: (1) a dilator140; (2) a tear-away sheath hub 111; (3) a tear-away valve 113; and (4)a tear-away sheath 130. The dilator 140 facilitates insertion of thesheath introducer 100 into the vascular system and maintains the insidediameter of the sheath 130 during insertion. The dilator 140 is normallylocked into the hub 111 in order to keep it seated within the sheath130. The dilator 140 typically contains a tapered tip to facilitateinsertion into the vascular system with the proximal end 144 of thedilator 140 containing a standard medical luer hub 146. Both the distalend 142 and the proximal end 144 of the dilator 140 are usuallymanufactured of a rigid polymer.

The tear-away hub 111 provides a means to contain the valve 113 whileconnecting the valve 113 and the sheath 130. The hub 111 typically has a“T” shape with the opposing ends of the “T” being grasped and pulled tosplit both the valve 113 and sheath 130. Thus, the hub 111 provides amechanism to split the sheath 130 into two portions and allow theintroducer to be split and removed from around the catheter. The hub 111also often manufactured of a rigid polymer.

The tear-away valve 113, however, is typically made of a flexiblematerial (such as silicone) that provides a self-sealing slit. The valve113 may be designed as one piece that tears in half during the splittingprocedure, or as two (or more) pieces that separate from each otherduring the splitting procedure. With conventional introducers, the valve113 is encapsulated by the hub 111.

The tear-away sheath 130 is normally manufactured as a thin-walledstructure, often as an extrusion. The extrusion contains splittingmeans, i.e., score lines that facilitate splitting or a self-splittingpropagating material (such as linearly-directional extrusion). Theproximal end 132 of the sheath 130 is attached to the hub 111 usingover-molding or any other known attachment mechanism. The distal end 134of the sheath 130 can be tapered to provide a smooth transition at thedilator/sheath interface.

To use the introducer 100, it is inserted in the desired vessel. Thenthe dilator 140 is unlocked from the hub 111 and removed to allow roomfor a catheter (or any similar medical device) to be inserted into thesheath. The valve 113 remains stationary inside the hub 111 and blocksair and/or fluid from flowing through the sheath 130 and hub 111 whenthey are left behind after the dilator is removed. The valve 113 keepsthe passage 105 clear until a catheter is inserted into the passage 105through the valve.

The introducer 100 is typically used for larger catheters, i.e., thosewith a diameter of 12 to 16 French. These larger-diameter introducersare rigid due to their diameter and the material used to construct them.This rigidity allows the large catheters to overcome the frictionalforces needed to push the catheter through the valve.

But inserting smaller catheters into smaller introducers is moredifficult. Typical introducers designed for smaller catheters (i.e.,those 3 to 12 French in diameter) are made with open communicationbetween the access site and the vascular system once the dilator isremoved. This open configuration exists because smaller catheters, dueto their smaller diameter and material, are not rigid enough to overcomethe frictional forces needed to push the catheter through the valve. Inother words, it is like trying to “push” a rope through a hole: the rope(i.e., catheter) does not remain rigid enough for a user to push itthrough the hole (i.e., valve).

The open configuration between the vascular system and the environment,however, allows two serious clinical problems. First, air embolism intothe vascular system which can result in patient injury and/or death. Andsecond, release of potentially infectious bodily fluids (includingblood) into the environment, resulting in exposure to the health careprovider.

SUMMARY OF THE INVENTION

The invention relates to tear-away and non-tear-away sheath introducersfor catheters, methods for making such introducers, and methods forusing such introducers. The sheath introducers contain movable valvesthat are encapsulated in a movable housing that allows the valve to movealong the axis of the introducer. As the movable valve and housingtravel along the axis, a portion of the hub protrudes past the valve andis exposed. As well, the sheath introducers can also contain astationary valve and housing that can be opened to expose a portion ofthe hub when a conduit penetrates the stationary valve. In bothinstances, the protruding portion of the hub contains a friction-freepathway for a catheter into the sheath introducer. The introducers cantherefore be used with any catheter, regardless of the size or material,because of the reduced or eliminated frictional force between thecatheter and introducer.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description of the invention can be understood in light ofFIGS. 1-23, in which:

FIG. 1 is a side perspective view(s) of the introducer assembly in oneaspect of the invention;

FIG. 2 is a side perspective view of a two-piece flexible valve in oneaspect of the invention;

FIG. 3 is a side perspective view of a dilator in one aspect of theinvention;

FIGS. 4 and 5 are section views of a valve housing in one aspect of theinvention;

FIGS. 6 and 7 depict the introducer assembly in another aspect of theinvention;

FIG. 8 is a side view(s) of the sheath introducer in another aspect ofthe invention;

FIG. 9 is a side perspective view(s) of the sheath introducer in evenanother aspect of the invention;

FIG. 10 is a side perspective view(s) of the sheath introducer in yetanother aspect of the invention;

FIGS. 11-12 show a single-piece valve in another aspect of theinvention;

FIGS. 13-14 depict view(s) of the single-piece valve and sheath hub inanother aspect of the invention;

FIGS. 15-17 depict view(s) of methods of increasing the attachmentbetween the sheath and the sheath hub in another aspect of theinvention;

FIG. 18 shows the operation or the sheath introducer in one aspect ofthe invention;

FIG. 19 illustrates a conventional sheath introducer;

FIGS. 20-21 depict view(s) of methods of increasing the attachmentbetween the sheath and the sheath hub in another aspect of theinvention; and

FIGS. 22-23 illustrate an introducer containing a stationary valve thatis opened by a movable conduit.

FIGS. 1-23 presented in conjunction with this description are views ofonly particular—rather than complete—portions of the devices andassociated methods of making and using these devices. Together with thefollowing description, the Figures demonstrate and explain theprinciples of the devices and associated methods. In the Figures, thethickness of layers and regions are exaggerated for clarity. The samereference numerals in different drawings represent the same element, andthus their descriptions will be omitted.

DETAILED DESCRIPTION OF THE INVENTION

The following description provides specific details in order to providea thorough understanding of the invention. The skilled artisan, however,would understand that the invention could be practiced without employingthese specific details. Indeed, the invention can be practiced bymodifying the illustrated method and resulting device and can be used inconjunction with apparatus and techniques conventionally used in theindustry. For example, the invention is described as a micro-introducerfor small catheters (3F-10F in size), but could easily be adapted forany size of catheter or device regardless of the size or intended use.Further, while the invention is described for use with catheters forvascular access, it could be used with any similar device that is usedto grant a physician (or other user) access to a part of the body,whether human or animal.

The invention includes a tear-away or non-tear-away sheath introducerthat contains a movable valve and housing that when moved, allows aportion of the hub to protrude through a valve and be exposed. Theprotruding portion of the hub contains a friction-free pathway for thecatheter. Any inducer having these properties can be used in theinvention, including the sheath introducer described below andillustrated in the Figures.

The sheath introducer of the invention contains several primarycomponents. First, dilator means used to dilate the vascular system andcreate a pathway for the catheter. Second, means for sheathing thedilator means to protect it from the vascular system. And third, valvemeans for keeping the pathway created by the dilator closed until thecatheter needs to be inserted.

One example of the sheath introducer is illustrated in FIG. 1 where theintroducer 10 contains dilation means comprised of a dilator hub 1 and adilator shaft 2. The dilation means is configured to fit within thesheath means comprised of a sheath hub 7 and a sheath 8. The introducer10 also contains valve means comprised of a valve with left and righthalves (4 and 5) contained within a valve housing having left and righthalves (3 and 6) that is attached to the sheath hub 7.

FIGS. 2-5 illustrate detailed views of each of these components. FIG. 2depicts one half of the valve 4, FIG. 3 illustrates the dilator hub 1,and FIGS. 4-5 shows the different views of one half of the valve housing3. In FIG. 2, the valve contains retention means for retaining the valveto the valve housing. Any retention means known in the art can be used,including retention member 12 which seats into a corresponding structurein the valve housing such as the valve retention slot 15. The valve hasa size and shape substantially the same as the inner part of the valvehousing to which it is retained. Accordingly, the valve half 4 depictedin FIG. 2 is substantially circular and with a size that fits within thecorresponding inner surface of the valve housing 3 shown in FIGS. 4-5.The valve can be manufactured from any suitable medical material,including flexible materials like silicone or polyurethane.

FIG. 3 depicts one example of a dilator of the introducer 10. Thedilator 31 can contain any standard medical luer hub, including adilator hub 1 with a gripping mechanism (such as finger grips 11) andlocking mechanism (such as locking ears 9) as shown in FIG. 3. Thelocking mechanism 9 locks the dilator 31 into the valve housing byusing, for example, the locking channel 16 contained in the valvehousing 3 and 6. The dilator 31 also contains a shaft 2 with a taperedsection for dilating the vessel into which it is inserted. The dilator31 can also be manufactured from any suitable medical material, butshould be made fairly rigid, yet flexible enough that it can bemaneuvered into the desired vessel by a user.

FIGS. 4 and 5 depict one example of the internal geometry of the valvehousing 3. The valve housing 3 contains any means for securing the valvehousing to the sheath hub 7. In FIGS. 4 and 5, the securing meanscomprises snap features 13, which secure the valve housing 3 to thesheath hub 7 using the mating snap feature 21 (shown in FIG. 6). Usingthe securing means keeps the valve housing (and therefore the valve) ina closed position until it is needed to be opened (i.e., such as whenthe catheter is inserted).

The valve housing 3 also contains any known means for positioning itwith the sheath hub 7. An example of this positioning means is depictedin FIGS. 4 and 5, where a guide slot 15 and stop post 20 mate with theguidepost 22 of the sheath hub 7 (shown in FIG. 6). The exterior of thevalve housing 3 contains grips 14 that can be employed by the user inthe splitting procedure. The valve housing 3 is constructed of anysuitable medical material that provides the desired rigidity, such asrigid polymeric materials.

The valve housing 3 can also contain any known interlock mechanismbetween the two halves of the valve housing. An example of thisinterlock mechanism is lock 19 that, when the halves are assembledtogether, serves to maintain uniform travel between both halves of thevalve housing. This interlock mechanism can be supplemented with anyknown mechanism, including the detachable interlock features 17 and 18.

FIGS. 6 and 7 illustrate the various components of the introducer whenassembled together. In FIGS. 6 and 7, the sheath hub 7 and the sheath 8are attached together into an assembly by any attachment means. Examplesof suitable attachment means include insert molding or any mechanicalattachment, such as a friction fit, locking snap fit, solvent or UVbond.

The sheath hub 7 contains several features for its operation. One suchfeature includes valve snap fit grooves and edges 21. These twocomponents, along with the snap feature 13, work together to snap thevalve housing 3 (and 6) to the sheath hub 7. Of course, any similarmechanism can be used to snap these two components to each other. Thesheath hub 7 also contains the guide slot 22, as mentioned above, thatguides the valve housing 3 (and 6) and the hub to the correct locationrelative to each other.

The sheath hub 7 also contains a valve penetration means. The valvepenetration means operates to penetrate the two halves of the valve 4and 5, thereby providing an opening in the valve. Any penetration meansknown in the art can be used for this function. As depicted in FIGS. 6and 7, the penetration means comprise penetration member 23 that isconfigured to fit between the two halves 4 and 5 of the valve. Thepenetration member 23 opens the two halves 4 and 5 of the valve when itis forced between them by any action which pushes the penetration member23 through the valve.

The valve penetration means need not physically force (i.e., push) thevalve halves 4 and 5 apart to penetrate the valve. In this aspect thepenetration member 23 penetrates the valve halves 4 and 5 when the valvehousings are pulled apart to expose the penetration member 23. The valvehousings 3 and 6 can be pulled apart by the mechanisms described below.

When the penetration member 23 opens the valve in either of thesemanners, port 24 is exposed. The port 24 is the location where thecatheter (or similar device) is inserted. Unlike the conventionalintroducers where the catheter is forced between the valve (whichcreates a friction force that must be overcome by a user), the cathetercan be inserted in the port 24 of the introducers. The port 24 can beconfigured to have less friction than that required in conventionaldevices by providing an inside diameter slightly larger than that of thecatheter insertion member. Alternatively, the port can be configured tohave substantially no friction (“friction-free”) by providing an insidediameter significantly larger than that of the catheter insertionmember. As well, the port 24 can be configured to have less orsubstantially no friction by providing a coating on the inside of theport 24 and/or the outside of the catheter.

The sheath hub 7 also contains activation means. The activation means isused to force the penetration member 23 up through the valve halves 4and 5, move the valve halves (and housing) down over the penetrationmember 23, or to pull the valve halves 4 and 5 apart, to thereby openthem and expose penetration member 23 containing port 24. Any mechanismthat operates in this manner can be use as the activation means. In thesheath hub depicted in FIG. 7, the activation means pulls the valvehalves 4 and 5 apart and comprises a reaction force member 25 that isformed on the bottom edge of the sheath hub 7. When pressure is appliedto the reaction force member 25 by the user, it depresses the valvehousings 3 and 6 and forces the valve halves 4 and 5 apart. Of course,any other known mechanism could be used to push or pull the valve apart.

FIG. 8 depicts the introducer in a position ready to accept a catheter.In FIG. 8, the penetration member 23 protrudes out of the valve halves 4and 5. The penetration member 23 need only protrude enough so that port24 is exposed enough for a catheter to be inserted. Typically, the port24 protrudes from about 0.025 to about 0.05 inches above the valve. Inone aspect of the invention, the port 24 protrudes about 0.05 inchesabove the valve.

FIG. 9 depicts one part of a method for using the introducer 10. Afterthe introducer 10 has been inserted into the desired vessel, thecatheter (not shown) is inserted through the introducer 10. Then, theuser presses on the grips 14 to cause the valve housing 3 and 6 toseparate from each other. As the pressing continues, the valve halves 4and 5 and the sheath hub 7 then separate from each other. Once thisinitial separation has occurred, the user can continue pull on the endsof the separated portions to continue separating the introducer 10.

FIG. 10 illustrates another part of a method for using the introducer10. In step 1, the introducer 10 has been inserted in the desired partof the vascular system, i.e., the desired vessel. Next, as shown in step2, the dilator is then removed from the introducer 10. As shown in step3, removing the dilator still leaves the valve in a closed position.Next, using the actuating mechanism a user makes the penetration member23 penetrate the valve in any of the methods described above so thatvalve is opened with the port 24 exposed. Then, the catheter (not shown)is inserted into the introducer as shown in step 4. Finally, theintroducer is removed by the splitting procedure as shown in step 5.

In some embodiments, the introducer can be configured so that the valveis stationary. In these embodiments, the stationary valve can be openedto expose a portion of a hub when conduit means penetrate the stationaryvalve. With a portion of the hub exposed, the catheter can then beinserted as described above.

One example of these embodiments is illustrated in FIGS. 22-23. FIG. 22depicts an assembled introducer 105 without a dilator. The assembledintroducer 105 contains a sheath hub bottom 107 containing a sheath hubtop 108, and valve means comprised of a stationary valve 104 containedwithin a valve housing 106. The assembled introducer 105 also containsconduit means (i.e., conduit 110) that can move along the axis of theassembled introducer 105. The conduit member 110 includes a cylindricalportion 116 and a conical portion 117.

The valve 104 can be configured to be stationary within the assembledintroducer 105 using any known mechanism. In the embodiments illustratedin FIGS. 22-23, the valve 104 is configured to be stationary by matchingthe extensions 112 of the valve 104 with corresponding indentations 114within a press fit generated between the sheath hub top 118 and valvehousing 106. In other instances, though, the extensions 112 could beconfigured to match indentations made in the valve housing 106 (notshown). In yet other instances, the valve 104 can be configured to bestationary by means of any known adhesive.

The valve housing 106 houses the stationary valve 104 and therefore thebottom of the valve housing 106 can be configured to substantially matchthe shape of the valve 104. As well, since the valve housing 106 islocated on the sheath hub top 118, the bottom of the valve housing 106can be configured to substantially match the upper surface of the sheathhub top 118. As depicted in FIG. 22, these matching surfaces can besubstantially flat. But any other matching shapes for these surfaces canbe used, including ridged, notched, or an interlocking snap fit.

The valve housing 106 also surrounds the conduit means (i.e., conduit110). Accordingly, the inner surface of the valve housing can beconfigured to substantially match the outer surface of the conduit 110.As depicted in FIG. 22, these two matching surfaces can be configured assubstantially circular in shape. But other geometries for these surfacescan be used, including substantially rectangular, substantially oval,substantially polygonal, or a male/female keyway.

The conduit 110 moves along the axis of the assembled introducer 105from a first position shown in FIG. 22 to a second position shown inFIG. 23. In the first position, the bottom 115 of the conduit 110remains above the closed valve 104. In the second position, the bottom115 of the conduit 110 has pierced the valve 104 and forced the valve104 into an open position. With the valve 104 in this open position, acatheter can be inserted though the conduit 110 and into the sheath 108.

In other embodiments, the conduit 110 can move into an intermediateposition anywhere between the first and second positions. Theintermediate position can be selected so that the valve 104 is opened byany desired amount. For example, the intermediate position for theconduit 110 can be selected so that a partially opened valve would allowonly a small amount of blood to be exposed, ensuring that the assembledintroducer 105 was located correctly in a vein.

The conduit means can have any configuration allowing it to operate inthis manner. Thus, the outer surface of the conduit 110 can beconfigured to be slightly smaller than the inner surface of the valvehousing 106, allowing the conduit 110 to move easily relative to thevalve housing 106. If desired, additional mechanisms like depth controldetents, springs, or coatings can be used to increase—or, if necessary,decrease—the ability of the outer surface of the conduit to moverelative to the inner surface of the valve housing 106.

In some instances, the outer surface of the conduit 110 and the innersurface of the valve housing 106 can be configured so that the conduitcan be retained in the first and second positions. Any retaining meansknown in the art can be used, such as markings, depth control detents,springs, threads or the retaining means illustrated in FIGS. 22-23. Inthese Figures, the retaining means comprises at least one notch 121 onthe outer surface of the conduit 110 that substantially matchesindentations 123 and 125 on the inner surface of the valve housing 106.The two (or more) sets of indentations are located where the notch 121will insert when the conduit 110 is in the first and second positions.

The bottom 115 of the conduit 110 can be configured so that it piercesand opens the stationary valve 104. Thus, the bottom 115 of the conduitcan be configured with any shape that will operates in this manner. Insome instances, the bottom 115 is typically given a substantiallypointed or substantially tapered shape. The bottom of the conduit cantherefore initially open the valve and as the conduit moves furtherdown, the opening in the valve becomes wider and wider allowing for asubstantially friction-free passage way through the valve. In someinstances, the bottom of the conduit can be rounded to prevent damage tothe valve.

The top 127 of the conduit 110 can be configured with any shape so thatit guides the placement of the catheter. One example of such a shape isdepicted in FIGS. 22 and 23 where the top of the conduit comprises asubstantial conical shape. The conical shape guides the placement of thecatheter through the top of the conduit and into the inner chamber 120of the conduit 110. The conical shape can, in certain instances, besmooth and rounded so that it is easier to be pushed by a user to openthe valve.

Once the assembled introducer 105 is located in the desired location,the user can open the valve easily by pressing on the top of the conduitmeans. This action forces the conduit 110 from the first position intothe second position, and opens the valve. The user can then place thetip of a catheter in the top of the conduit. As the user pushes on thecatheter, the tip is guided from the top of the conduit 110, though theinner chamber 120, past the opened valve, out the bottom of the conduit,and then into the sheath 108.

The introducers described above can be modified and enhanced withseveral optional features. One of these modifications is a modifiedvalve 30 as depicted in FIGS. 11 and 12 that comprises a base 32,extensions 34, and channel portion 36. The base 32 of the valve 30 isconfigured with a size and shape substantially similar to the valvehousing in which the valve 30 rests. The valve 30 can optionally containan indentation 35 of any shape and size that will help the valve split.

The extensions 34 are designed to extend upwards from the valve 30towards the dilator of the introducer. Like the base 32, the extensions34 will abut the valve housing, but the sides rather than the bottom.Accordingly, the size and shape of the extensions 34 are selected tosubstantially match the inner surface of the valve housing which willenclose the valve 30. The extensions 34 contain a notch(es) 38 thatcorrespond to the notches 50 provided in the protruding member 41 (asdescribed below).

The channel portion 36 of the valve 30 also extends in an upwarddirection toward the dilator of the introducer. As shown in FIG. 12, theinner surface 37 of the channel portion 36 will abut the outer surfaceof the outside of the protruding member 41 and is accordingly given asize and shape substantially matching the protruding member 41. Thelength of the channel portion 36 is also selected to substantially matchthe protruding member 41 so that port 44 can be exposed when desired.

The upper surface 42 of the channel portion contains a slit 40. The slit40 does not extend the entire way across the channel portion 36 and sois a non-tear away slit. The slit 40 is held in a closed or sealedposition (position A in FIG. 13) by the valve housing and sheath hub.The slit 40 moves into an open position B when the protruding member 41moves upward through the channel portion 36 and then up through the slit40 (or the valve 30 moves downward over the member 41) as depicted inFIG. 13. Of course, as described above, the valve 30 can be pulled apartto expose the protruding member 41 rather than forced apart.

The channel portion 36 of the valve 30 can also operate as a sealingmeans around the protruding member 41. The sealing means helps provide aseal between the vascular system and the environment when the protrudingmember 41 has forced the slit 40 open. This sealing function isillustrated in FIG. 13 where the protruding member 41 is shown in itsextended state, i.e., protruding above the valve 30. The channel portion36 fits snugly around protruding member 41 so that it provides a seal.Optionally, a coating can be added to the inside of the channel portion36 and/or the outside of the protruding member 41 to increase thissealing function. As shown in FIG. 12, the channel portion 36 canoptionally contain a ring sealing member(s) 39 to increase the sealingfunction.

The advantage of valve 30 is that it can also serve as a flash-backchamber. If the valve 30 (and associated parts of the hub sheath) ismade from a translucent or transparent material, it allows the user toview the inside of the valve 30. If sheath introducer 10 is placed inthe proper location (i.e., in the venous system), blood will enter thevalve chamber resulting in a red color as an indication that the sheathintroducer is placed correctly. Using a translucent or transparentmaterial for the valve 30 therefore allows the user to look through thevalve and determine whether this red color is showing.

As mentioned above, a seal can be formed between the channel portion 36and the protruding member 41. To help improve the seal between these twocomponents, the protruding member 41 can be modified by providing stressrisers (45 and 46) on the inside 40 and the outside 41 of the protrudingmember 41 as shown in FIG. 14. The internal stress riser 46 provides asmooth surface at the interface with the valve ring sealing member 39.As noted above, the valve ring sealing member 39 can provide a seal asthe valve translates along the stem. Moving from the bottom to the topof the protruding member 41, the riser(s) 45 begin on the outside andthen move to the inside 46, allowing the splitting mechanism (crack) toprogress while maintaining a smooth outer surface between the valve ringsealing member 39 and the protruding member 41.

The stress riser 45 begins on the bottom of the sheath hub 47 andcontinues along the outside of the sheath hub until the stress riser 45reaches a point below the initial location of the valve ring sealingmember 39. At that point, the stress riser 46 moves to the inside of theprotruding member 41 and then continues to the notch 50. The depth andwidth of the stress risers 45 and 46 are selected depending on therequired separation force.

Another function of the stress risers 45 and 46 are to act as aninitiator in the splitting process. By their nature, the stress risersare the beginning of a split in the hub sheath 47 and, therefore, can beused to make the splitting process easier. Accordingly, the stressrisers 45 and 46 are located substantially on the axis where theintroducer 10 will be split.

Another optional modification that can be made to the sheath introducercomprises notches 50 in the upper portion of the protruding member 41that remain above the valve 30 in the extended position. The notches 50give the protruding member 41 additional length to extend past the valve30 while at the same time not adding additional length to the stressrisers 45 and 46. Such a configuration adds length to the protrudingmember 41 without increasing the cracking force needed to split theintroducer 10.

As shown in FIG. 14, the notches 50 are generally made to correspondwith the same location as the stress risers 45 and 46, i.e.,substantially along the axis of the expected split. The notches 50 canhave any shape that results in a concentration of the stress force.Examples of such shapes include substantial “V” shape or the substantialrectangular shape shown in FIG. 14.

The sheath hub 47 can also be optionally modified to increase theattachment between the sheath hub 47 and the sheath 53. One manner toincrease this attachment is depicted in FIGS. 15 and 16. In FIG. 15, thesheath has been modified to contain a sheath cap 57 with an interlockingfit between the sheath 53 and the sheath cap 57. The sheath cap 57contains grooves 58 which provide a location for the split ends 55 ofthe sheath 53 when the sheath is inserted though the sheath cap 57. Theends of the split sheath fold around the sheath retention cap 57 withtheir location maintained in the grooves 58. Once the sheath retentioncap 57 is assembled into the mating geometry of the sheath hub 47 asshown in FIG. 16, it locks the ends 55 of the split sheath tightly intothe hub 47. The sheath cap 57 is then affixed to the sheath hub 47.

In some embodiments, the sheath cap 57 can affixed to the sheath hub 47by means of a thermal, solvent or UV bond. In other embodiments, thesheath cap 57 can be affixed to the sheath hub 47 using a mechanicalconnection as known in the art, including a friction fit, snap fit, orultrasonic weld. One example of such a mechanical connection isillustrated in FIG. 20, where the sheath hub 47 had been provided with aconnector 72 containing male connections 71. The sheath cap 57 has alsobeen provided with a corresponding shape and size that will mate withthe connector 72, including female connections 73. When the sheath cap57 is moved towards the sheath hub 47, the male connection 71 slidesinto the female connection 73 and attaches the hub 47 and the cap 57 toeach other. Because of its shape, the cap 57 will also mate with theconnector 72 and can be configured, as shown in FIG. 20, to retain theends 74 of the sheath 53 between them.

Another method to increase the attachment sheath hub 47 and the sheath53 is illustrated in FIG. 21. As shown in FIG. 21, the sheath cap 57 hasbeen modified to contain extensions 75 that run substantially parallelto the body of the sheath hub 47. The extensions 75 have been configuredto substantially match the body of sheath hub 47. Likewise, the body ofsheath hub 47 has been configured to match the extensions of sheath cap57. Although many matching configurations can be used, the extensions 75contain ridges 77 that will substantially match notches 79 in the sheathhub. When the sheath cap 57 is moved towards the sheath hub 47, theridges 77 slides into the notches 79 and attaches the hub 47 and the cap57 to each other.

A similar, but different, configuration is depicted in FIGS. 22-23. Inthese Figures, the sheath hub bottom 107 has been modified to containextensions 175 that run substantially parallel to the body of the sheathhub top 118. The extensions 175 have been configured to substantiallymatch the body of sheath hub top 118. Likewise, the body of sheath hubtop 118 has been configured to match the extensions of sheath hub bottom107. Although many matching configurations can be used, the extensions175 contain ridges 177 that will substantially match notches 179 in thesheath hub top 118 and then wrap over the ends 180 of the sheath hubbottom 107. When the sheath hub bottom 107 is moved towards the sheathhub top 118, the ridges 177 slides into the notches 179 and attaches thesheath hub top 118 and the sheath hub bottom 107 to each other, with thewrapping portions of the sheath hub bottom 107 aiding the attachment.

Alternatively, another method to increase this attachment is depicted inFIG. 17. In FIG. 17, the sheath hub 47 has been modified to encapsulatean end portion of the sheath 53. This encapsulation is performed so thatridges 59 overly the end 56 of the sheath 53, thereby retaining the endof the sheath underneath the ridges.

In yet another modification, the sheath introducer can be provided withmeans for separating the valve housing 33 away from the sheath hub 47.Any known means for forcing these two components apart can be used inthe invention, including leaf spring, coil spring, hinge, and/or amechanical lever. As depicted in FIG. 18, the forcing means comprises aspring 65. In its compressed state, the valve housing 33 and the sheathhub 47 are attached to each other by any mechanism, such as the snapfeatures 13 and 21 mentioned above and/or the lever 66. When the valvehousing 33 and the sheath hub 47 are attached, the valve 30 remainsclosed. The moment the user separates the sheath hub 47 from the valvehousing 33 by pressing on the grip section 52 (and/or disengaging thelever 66), the spring 65 is released from its compressed state and thesetwo components separate from each other.

One result of the separation of these two components is the movement ofvalve 30 relative to the protruding member 41. When these two componentsare attached to each other, the spring is compressed and the valve 30slides down the protruding member which then opens the slit 40 of thevalve 30. When these components are separated, the pressure of thespring 65 is released and it returns to the uncompressed state, slidingthe valve 30 back up the protruding member and closing the slit 40.

In another modification, the valve housing of the introducer could beengaged by means of a rotary movement along the axis of a threadedmember or any other mechanical means to translate the valve housingalong the desired path. For example, a mechanical lever, push button, orthreaded member could be used in this modification.

In addition to any previously indicated variation, numerous othermodifications and alternative arrangements may be devised by thoseskilled in the art without departing from the spirit and scope of theinvention and appended claims are intended to cover such modificationsand arrangements. Thus, while the invention has been described abovewith particularity and detail in connection with what is presentlydeemed to be the most practical and preferred aspects of the invention,it will be apparent to those of ordinary skill in the art that numerousmodifications, including but not limited to, form, function, manner ofoperations and use may be made without departing form the principles andconcepts set forth herein.

What is claimed is:
 1. A sheath introducer, comprising: a splittablesheath extending from a sheath hub; a valve housing coupled to thesheath hub, a stationary valve positioned within the valve housing, thevalve housing comprising: a continuous inner surface defining a lumen;an outer wall enclosing the entire lumen; and a proximal opening; and aconduit member having a cylindrical portion, the conduit member movablewithin the valve housing from a first position in which a proximalsection of the conduit member extends outside of the proximal opening ofthe valve housing and the valve is closed to a second position in whicha distal end of the conduit member penetrates the valve to open thevalve and the proximal section of the conduit member and the cylindricalportion is positioned substantially within the valve housing.
 2. Thesheath introducer of claim 1, further comprising a retaining means,wherein the conduit member includes a first retaining feature of theretaining means on an outer surface thereof, and wherein a secondretaining feature of the retaining means is positioned on the innersurface of the valve housing.
 3. The sheath introducer of claim 2,wherein the second retaining feature comprises at least two spaced apartformations on the inner surface of the valve housing to retain theconduit member in different positions with respect to the valve.
 4. Thesheath introducer of claim 1, wherein the conduit member comprises asubstantially rigid material.
 5. The sheath introducer of claim 1,wherein the valve comprises a substantially flexible material.
 6. Thesheath introducer of claim 1, wherein the distal end of the conduitmember is a distal end of a conical portion of the conduit member. 7.The sheath introducer of claim 1, wherein a proximal end of the conduitmember comprises a passage having a substantially conical shape.
 8. Asheath introducer for a catheter, comprising: a splittable sheathextending from a sheath hub; a valve housing coupled to the sheath hub,a stationary valve positioned within the valve housing, the valvehousing having a continuous inner surface defining a lumen and an outerwall enclosing the entire lumen; and a conduit member movable withrespect to the valve and the valve housing from a first position inwhich a proximal end of the conduit member extends outside of the valvehousing and the valve is closed to a second position in which theconduit member penetrates the valve to open the valve, the conduitmember including a conical portion extending distally from a cylindricalportion, the conical portion having an outer diameter at a proximal endthereof less than an outer diameter of the cylindrical portion theconical portion including a tapered section along at least a distal endthereof, a proximal section of the conduit member and the cylindricalportion positioned substantially within the valve housing in the secondposition.
 9. The sheath introducer of claim 8, wherein the conduitmember comprises a friction-reduced insertion port.
 10. The sheathintroducer of claim 9, wherein a distal end of the conical portion ofthe conduit member comprises a tip that penetrates the valve, andwherein a proximal end of the conduit member comprises a passage havinga substantially conical shape.
 11. The sheath introducer of claim 8,wherein the valve forms a seal around the conduit member when it is inthe second position.
 12. A system for inserting a catheter into a body,the system comprising a sheath introducer containing: a stationaryvalve; a valve housing, including: a continuous inner surface defining alumen; an outer wall enclosing the entire lumen; and a proximal opening;and a conduit member having a cylindrical portion, the conduit memberpositioned in the valve housing lumen, the conduit member having aproximal section extending outside of the valve housing from theproximal opening in a first position in which the valve is closed, theconduit member movable within the valve housing lumen from the firstposition to a second position in which a distal end of the conduitmember penetrates the valve to open the valve prior to the catheterbeing inserted through the sheath introducer to provide a substantiallyfriction-free passage way through the valve, the proximal section of theconduit member and the cylindrical portion positioned substantiallywithin the valve housing in the second position.
 13. The sheathintroducer of claim 12, further comprising a retaining means, whereinthe conduit member includes a first retaining feature of the retainingmeans on an outer surface thereof, and wherein a second retainingfeature of the retaining means is positioned on an inner surface of thevalve housing.
 14. The sheath introducer of claim 13, wherein the distalend of the conduit member that penetrates the valve is a distal end of aconical portion of the conduit member, and wherein a proximal end of theconduit member comprises a passage having a substantially conical shape.15. A method for making a sheath introducer, the method comprising:providing a stationary valve; providing a valve housing including: acontinuous inner surface defining a lumen; an outer wall enclosing thelumen; and a first retaining feature associated with the inner surface,the valve positioned in the valve housing distal of the retainingfeature; and providing a conduit member in the valve housing lumen, thelumen surrounding the conduit member, the conduit member movable withinthe valve housing lumen from a first position in which a proximal end ofthe conduit member extends outside of the valve housing and the valve isclosed to a second position in which a distal end of the conduit memberpenetrates the valve to open the valve, the conduit member including asecond retaining feature on an outer surface thereof to cooperate withthe valve housing first retaining feature to retain the conduit memberin the second position.
 16. The method of claim 15, wherein the valvehousing retaining feature comprises at least two spaced apart formationsto retain the conduit member in an intermediate position between thefirst position and the second position.
 17. The method of claim 15,including providing the distal end of the conduit member with a conicalportion, and providing a proximal end of the conduit member with apassage having a substantial conical shape.